Shock-wave energy sources, such as explosive, gun powder, explosive gas, electric spark discharges or magnetic fields are used in a number of known ways to carry out useful work, such as the welding, moulding or compaction of metal and other material for instance.
One of the most serious problems with all of these working methods is that the tool has a short useful life.
The material from which the tool is made rapidly becomes fatigued, as a result of the shock wave which passes into the tool and which is reflected back from the free surfaces of the tool in the form of a tensile force wave.
Although the majority of materials from which such tools are made can withstand very high compaction forces, they are more sensitive to tensile forces.